DESCRIPTION: This application is designed to test the hypotheses that vagal sensory neurons that project to the stomach have collateral branches that also innervate the esophagus, and that direct communication between these peripheral branches may provide a direct neural link between the esophagus and the stomach. To test this hypothesis, the investigators will utilize a novel in vitro preparation that includes the stomach and subdiaphragmatic esophagus with the vagus nerves and branches intact. By recording from vagal fibers between the esophagus and the stomach, vagal sensory nerve fibers that conduct signals from the esophagus to the stomach, in addition to conducting signals from the stomach toward the nodose ganglion, can be identified and studied. The receptive fields of esophageal and gastric branches will be identified, and responses to pharmacological and mechanical manipulations can be evaluated. This preparation will be used to accomplish the aims of the proposal, which are to: 1) characterize the gastric vagal afferents to an extent that was not achievable using the standard in vivo approach; 2) identify and evaluate the esophageal and gastric components of the vagal afferent collateral reflex; and 3) investigate potential physiological roles of the axon reflex, such as a conditioning effect on gastric branches by activation of esophageal branches.